Cardiac Defects: ASD, VSD, and PDA

Sinus Venosus Defect (ASD 3)

• Opening near the junction of the superior vena cava
• May be asymptomatic or present with respiratory tract infections, dyspnea on exertion, and congestive heart failure
• May experience feeding difficulties
• Management options include cardiac catheterization or open heart surgery
• Surgical repair aims to reduce excessive pulmonary blood flow and protect pulmonary vasculature from hypertrophy and irreversible pulmonary hypertension

Ventricular Septal Defect (VSD)

• Abnormal opening between the right and left ventricles
• Small VSDs are usually asymptomatic and often close spontaneously during the first year of life
• Large VSDs can lead to congestive heart failure (CHF) with symptoms like tachypnea, tachycardia, excessive sweating, hepatomegaly, frequent upper respiratory infections, poor weight gain, failure to thrive, feeding difficulties, and decreased exercise tolerance

Patent Ductus Arteriosus (PDA)

• Failure of the fetal ductus arteriosus to close within the first weeks of life
• High risk factors include maternal rubella exposure during pregnancy
• Assessment includes a machinery-like murmur, asymptomatic presentation, and signs and symptoms of CHF and decreased cardiac output
• Management options include medical treatment with Indomethacin (Indocin) and surgical ligation

Obstructive Defects

• Blockage of blood flow in the heart due to narrowing (stenosis)
• Can result in decreased cardiac output, ventricular hypertrophy, and pulmonary vascular congestion

Aortic Stenosis

• Narrowing of the aortic valve causes resistance to blood flow in the left ventricle
• Assessment findings include a characteristic murmur and signs of decreased cardiac output in infants and exercise intolerance, chest pain, and dizziness when standing for long periods in children
• Treatment includes minimally invasive procedures like aortic valvotomy or valvuloplasty, and valve replacement

Coarctation of the Aorta

• Localized narrowing of the aorta
• Assessment includes absent femoral pulses, higher blood pressure in the upper extremities, and weaker or absent pulses in the lower extremities
• Management options include balloon angioplasty and surgical resection with end-to-end anastomosis of the aorta

Pulmonary Stenosis

• Narrowing at the entrance to the pulmonary artery causing resistance to blood flow
• Leads to right ventricular hypertrophy and decreased pulmonary blood flow
• Pulmonary atresia is the extreme form with total fusion of the commissures and no blood flow to the lungs
• Treatment includes balloon valvuloplasty and surgical valvotomy

Tetralogy of Fallot

• Four defects: pulmonary stenosis, VSD, overriding aorta, and supracardiac total anomalous pulmonary venous return (TAPVR)
• Assessment involves a characteristic murmur, moderate to severe CHF, variable cyanosis, poor growth, and activity intolerance
• Surgical treatment aims to close the VSD, implant a conduit and valve to connect the right ventricle with the pulmonary artery, and construct a single large vessel and aorta

TAPVR (Total Anomalous Pulmonary Venous Return)

• Pulmonary veins drain into the right atrium instead of the left
• Classified based on location: Supracardiac, Infracardiac, and Cardiac
• Blood mixes in the common great artery causing desaturation and hypoxemia
• Surgical treatment aims to create a connection between the pulmonary veins and the left atrium

Venous Thromboembolism (VTE)

• Deep vein thrombosis (DVT) and pulmonary embolism
• Often clinically silent and frequently underdiagnosed
• Risk factors include endothelial damage, venous stasis, and altered coagulation
• Pathophysiology follows Virchow's triad: endothelial damage, venous stasis, and altered coagulation
• Deep veins may show edema, warmth, and prominence, while superficial veins may present with tenderness, redness, and warmth
• Diagnostic exams include careful assessment of lower extremities and Homan's sign (although not entirely reliable)
• Prevention measures include identification of risk factors, compression stockings and devices, early ambulation, leg exercises, low molecular weight heparin (LMWH), and lifestyle changes
• Medical management aims to prevent thrombus growth and fragmentation
• Nursing management includes monitoring for complications, providing comfort, and encouraging exercise

Polycythemia

• Classified as primary (Polycythemia Vera) or secondary
• Primary Polycythemia Vera is due to a mutation leading to overproduction of red blood cells
• Secondary Polycythemia occurs due to factors reducing oxygen reaching tissues, like smoking, high altitude, or congenital heart disease
• Diagnosis includes elevated hemoglobin, positive JAK2 gene, and decreased serum erythropoietin
• Clinical manifestations include ruddy complexion, splenomegaly, and symptoms from increased blood volume
• Medical management for Primary Polycythemia Vera focuses on reducing risk of thrombosis and bleeding, and treating contributing factors
• Medical management for Secondary Polycythemia involves treating the underlying condition and therapeutic phlebotomy

Hemophilia

• Group of bleeding disorders due to deficiency of specific coagulation proteins
• Most common types include Hemophilia A and Hemophilia B
• Characterized by excessive bleeding and prolonged clotting time
• Treatment involves replacement therapy with missing coagulation factor
• Management includes careful monitoring of blood coagulation factors and preventing bleeding episodes

Vascular Disorders

• Include conditions affecting blood vessels, such as venous thromboembolism and polycythemia
• Management focuses on addressing specific causes and complications

Explore the characteristics and management of common cardiac defects including Atrial Septal Defect (ASD), Ventricular Septal Defect (VSD), and Patent Ductus Arteriosus (PDA). Understand their symptoms, potential complications, and treatment options to enhance your knowledge in pediatric cardiology.